Adaptation of endoscopic submucosal dissection techniques for endoscopic full-thickness resection: a review of key steps and technical aspects.

Background and Aims: GI stromal tumors (GISTs) represent the most common mesenchymal tumors of the GI tract. Guidelines recommend the removal of histologically proven gastric GISTs >2 cm. While the conventional treatment of a gastric GIST involves surgical excision, endoscopic full-thickness resection (EFTR) has been described as an acceptable alternative. We aim to outline how the key steps used in endoscopic submucosal dissection (ESD) can be adapted to the performance of exposed EFTR and discuss the variations in technical aspects between the 2 procedures. Methods: We use a video case illustration with a comprehensive narrative to highlight the similarities and differences in equipment used and techniques in EFTR and ESD. Images and graphical illustrations are also used to describe these techniques. Results: ESD techniques and equipment can be adapted for use in EFTR of gastric GISTs. Principles such as deep mucosal incision, the appropriate use of traction, and identification of vessels for prophylactic coagulation help to ensure a safe and efficient procedure. The main difference in EFTR is the need for general anesthesia, starting the mucosal incision as close to the tumor margin as possible, submucosal dissection around the surface of the tumor capsule, and a strong closure method for the muscle defect. Conclusions: The equipment and techniques in ESD can be adapted to EFTR for gastric GISTs by endoscopists who are familiar with ESD techniques.

Risk of gastric adenoma and adenocarcinoma in patients with familial adenomatous polyposis in Japan: a nationwide multicenter study.

BACKGROUND: Patients with familial adenomatous polyposis (FAP) have an increased risk of developing gastric neoplasms. However, the clinical course of FAP with these gastric lesions has not yet been fully clarified. The present study aimed to clarify the changes in the incidence risk of developing gastric adenoma or gastric cancer during the lifespan of patients with FAP. METHODS: Four hundred forty-three patients with data regarding gastric adenoma and gastric cancer retrospectively registered in a nationwide Japanese multicenter study were enrolled. The cumulative incidences and hazard rates (HRs) of gastric neoplasms were evaluated. RESULTS: The cumulative incidence rates in 50-year-old patients with FAP were 22.8% for gastric adenoma and 7.6% for gastric cancer, respectively. No significant association was found between gastric neoplasms and the colonic phenotype. The peak age for the HR of gastric adenoma was 65 years, with the highest HR (0.043). Regarding the incidence of gastric cancer, the HR increased moderately up to the age of 40 years, but the increase accelerated from the age of 50 years (HR = 0.0067). CONCLUSION: Careful surveillance of the upper gastrointestinal tract in elderly patients with FAP, such as shortening the interval of follow-up according to age, may be helpful for early diagnosis of gastric cancer.

Endoscopist-related factors affecting adenoma detection during colonoscopy: Data from the J-SCOUT study.

OBJECTIVES: Colonoscopy withdrawal times are associated with the adenoma detection rate (ADR). However, the relationship between ADR and cecal insertion time has been inadequately characterized. We aimed to evaluate endoscopist-related factors involved in the ADR, including the average individual colonoscopy insertion and withdrawal times. METHODS: This observational study used a colonoscopy database with pathology data from routine clinical practice in Japanese institutions. The odds ratios (OR) of endoscopist-related factors related to ADRs were examined using a generalized linear mixed model. RESULTS: Of the 186,293 colonoscopies performed during the study period, 47,705 colonoscopies by 189 endoscopists in four hospitals were analyzed for ADR. The overall ADR was 38.3% (95% confidence interval [CI] 37.8, 38.7). Compared to endoscopists with mean cecal insertion times of <5 min, the OR of ADR for those with mean cecal insertion times of 5-9, 10-14, and ≥15 min were 0.84 (95% CI 0.71, 0.99), 0.68 (95% CI 0.52, 0.90), and 0.45 (95% CI 0.25, 0.78), respectively. Compared to endoscopists with mean withdrawal times of <6 min, the OR of ADR for those with mean withdrawal times of 6-9, 10-14, and ≥15 min were 1.38 (95% CI 1.03, 1.85), 1.48 (95% CI 1.09, 2.02), and 1.68 (95% CI 1.04, 2.61), respectively. There were no significant differences in ADRs by endoscopist specialty, gender, or the total number of examinations performed. CONCLUSION: Individual mean colonoscopy insertion time was associated with ADR and might be considered as a colonoscopy quality indicator as well as withdrawal time.

Predictors of technical difficulty for trainees in esophageal endoscopic submucosal dissection.

BACKGROUND: Esophageal endoscopic submucosal dissection (ESD) is technically challenging, especially for trainees, and requires a safe training system. This study aimed to identify predictors of technical difficulty facing trainees performing esophageal ESD to establish such system. METHODS: This was a single-center retrospective study of patients with esophageal cancer who underwent ESD performed by trainees between January 2010 and August 2022. Technical difficulties were defined as muscularis propria exposure and long procedure time (≥ 90 min). Factors associated with these technical difficulties were investigated. RESULTS: A total of 798 lesions in 721 patients were evaluated. Muscularis propria exposure occurred in 298 lesions (37.3%), including 10 perforations (1.3%). The procedure time was ≥ 90 min in 134 lesions (16.8%). In the multivariate analysis, tumor size ≥ 20 mm, tumors ≥ 1/2 of the circumference, and those close to previous treatment scars significantly increased the incidence of both difficulties, whereas tumors in the upper esophagus significantly decreased this incidence. Furthermore, female sex and tumors in the left wall were independent predictors of muscularis propria exposure, and elevated morphology was an independent predictor of long procedure time. Muscularis propria exposure and long procedure time occurred in more than half of the cases with three or more predictors of each difficulty. CONCLUSIONS: Large tumors and tumors close to previous treatment scars increase technical difficulties for trainees in esophageal ESD. Conversely, tumors in the upper esophagus reduce these difficulties. These results enable us to predict the difficulty level preoperatively and select appropriate cases in stepwise training.

Endoscopic full-thickness resection for gastric submucosal tumors: Japanese multicenter prospective study.

OBJECTIVES: Early gastric cancer endoscopic resection (ER) is prominent in Japan. However, evidence regarding ER of gastric submucosal tumors (SMT) is limited. This prospective multicenter phase II study investigated the efficacy and safety of endoscopic full-thickness resection (EFTR) for gastric SMT. METHODS: Endoscopic full-thickness resection indication for gastric SMT was 11-30 mm, histologically proven or clinically suspicious (irregular margin, increasing size, or internal heterogeneity) gastrointestinal stromal tumors (GIST), with no ulceration and intraluminal growth type. The primary end-point was the complete ER (ER0) rate, with a sample size of 42. RESULTS: We enrolled 46 patients with 46 lesions between September 2020 and May 2023 at seven Japanese institutions. The mean ± SD (range) endoscopic tumor size was 18.8 ± 4.5 (11-28) mm. The tumor resection and defect closure times were 54 ± 26 (22-125) min and 33 ± 28 (12-186) min, respectively. A 100% ER0 was achieved in all 46 patients. The EFTR procedure was accomplished in all patients without surgical intervention. One patient had delayed perforation and was managed endoscopically. GIST accounted for 76% (n = 35) of the cases. R0, R1, and RX rates were 33 (77%), 3 (6.5%), and 7 (15%), respectively. CONCLUSION: Endoscopic full-thickness resection for gastric SMT of 11-30 mm is efficacious. It warrants further validation in a large-scale cohort study to determine the long-term outcome of this treatment for patients with gastric GIST.

Potential role of a novel endoscopic retrieval bag for large colorectal resected specimen: a proof-of-concept study.

Endoscopic submucosal dissection enables en bloc resection of large superficial colorectal neoplasms. However, it is sometimes challenging to retrieve a large resected specimen via the anus without sample fragmentation. A novel "bag-type" retrieval device has been developed to accomplish complete isolation and non-destructive delivery of oversized specimens. This single-center retrospective study was performed to demonstrate the efficacy of this device for large colorectal resected specimens. Among 17 patients, we identified 18 superficial colorectal lesions for which the use of a novel retrieval device (Endo Carry Large Type) was indicated at specimen delivery at a referral cancer institute from March 2021 to July 2022. The median (interquartile range) tumor size was 62.5 (52.0-79.5) mm. Retrieval of 17 (94%) of 18 resected specimens was performed using the Endo Carry Large Type, and 16 (89%) were successfully retrieved without sample fragmentation. The median (interquartile range) retrieval time was 4 (4-8) minutes, and no apparent adverse events were observed. The novel Endo Carry Large Type device can accomplish colorectal specimen retrieval safely and quickly without specimen damage and therefore may contribute to accurate pathological diagnosis.

Resection of large terminal ileum polyp: usefulness of underwater EMR.

Video 1Underwater endoscopic mucosal resection for a large polyp at the terminal ileum.

Usefulness of genotyping APC gene for individualizing management of patients with familial adenomatous polyposis.

BACKGROUND: Colorectal polyp burden is crucial for the management of patients with familial adenomatous polyposis (FAP). However, accurate evaluation of polyp burden is difficult to standardize. This study aimed to examine the possible utility of genotype-oriented management of colorectal neoplasms in patients with FAP. METHODS: Clinicopathological data from genetically proven patients with FAP was analyzed using the database of a nationwide retrospective Japanese multicenter study. The cumulative incidence of CRC was evaluated between different genotype groups. Genotype-1 were defined as germline variants on attenuated FAP-associated regions (codons 1-177, alternative splice site of exon 10 (codon 312), 1581-2843) and Genotype-2 as the other variants. Weibull and Joinpoint analyses were performed to determine the annual percentage changes in CRC risk. RESULTS: Overall, 69 men and 102 women were included. Forty-eight patients underwent colorectal resection for the first CRC, and five patients underwent resection for first cancer in the remnant anorectal segment after prophylactic surgery. The 70-year cumulative incidence of CRC in all patients was 59.3%. Patients with Genotype-1 (n = 23) demonstrated a lower risk of CRC stages II-IV than those with Genotype-2 (n = 148, P = 0.04). The risk of stage II-IV CRC was estimated to increase markedly at the age of 49 years in the Genotype-1 patients and 34 years in the Genotype-2 patients, respectively. CONCLUSIONS: Different interventional strategies based on genotypes may be proposed for the clinical management of patients with FAP. This policy needs to be validated in further prospective studies focusing on long-term endoscopic intervention and optimal age at prophylactic (procto)colectomy.

Endoscopic features of gastric neuroendocrine carcinoma.

BACKGROUND AND AIM: The endoscopic features of gastric neuroendocrine carcinoma (G-NEC) have not been clarified; therefore, they were investigated in relation to clinicopathological findings. METHODS: Consecutive patients with G-NECs who had undergone endoscopic or surgical resection at our institution between January 2005 and March 2022 were included in this retrospective study. The endoscopic and clinicopathological findings of the lesions were analyzed to provide information of diagnostic value. In addition, cases of gastric neuroendocrine tumor (G-NET) and common-type gastric adenocarcinoma treated in the same study period were identified to compare the endoscopic findings between each G-NEC versus G-NET, and G-NEC versus common-type gastric adenocarcinoma. Patients with common-type gastric adenocarcinoma were matched for age, sex, tumor size, and depth of tumor invasion in 1:3 ratio. RESULTS: Among 15 patients with 15 G-NECs, submucosal tumor-like marginal elevation (87%), adherent white coat (67%), and ulceration with a distinct border (60%) were characteristic endoscopic findings in white-light images. Magnifying narrow-band imaging endoscopy revealed an absent microsurface (MS) pattern plus disrupted irregular microvessel (MV) in five (71%) of seven cases with evaluable MS and MV patterns. The area with an absent MS pattern plus disrupted irregular MV corresponded to the histological finding of NEC component in all five cases. These endoscopic features were all significantly more frequent in G-NECs than G-NETs (n = 22) or common-type gastric adenocarcinomas (n = 45). CONCLUSIONS: These endoscopic features should be taken into consideration to increase the index of suspicion and to improve the accuracy of target biopsies for G-NEC.

Multiple foci of dilated vessels as a new predictor of metachronous esophageal cancer.

OBJECTIVES: Prediction of the risk of esophageal squamous cell carcinoma (SCC) by endoscopic findings without iodine staining, which is irritating to the esophagus, would be beneficial. In a previous retrospective study, we found that multiple foci of dilated vascular areas (MDV) of the esophageal mucosa, seen in narrow-band imaging (NBI)/blue laser imaging (BLI), are associated with iodine-unstained lesions and, thus, may be a predictor of esophageal SCC. This prospective study aimed to investigate the association between MDV and metachronous esophageal SCC. METHODS: Patients with a history of endoscopic resection for esophageal SCC were included in the study. First, evaluation of the MDV using NBI or BLI was conducted during the initial endoscopy. The patients were then monitored for metachronous esophageal SCC by endoscopic surveillance. The association between the number of MDV and incidence of metachronous esophageal SCC was investigated. RESULTS: From February 2018 to May 2019, 206 patients were enrolled and 201 patients were included in the analysis. Patients were followed up until October 2022. The median (interquartile range) endoscopic follow-up period was 1260 (1105-1348) days. The incidence of metachronous esophageal SCC at 2 years was 7.1% in patients with MDV ≤4 and 13.9% in patients with MDV ≥5 (P < 0.01). In the multivariate analysis, MDV was an independent predictor of metachronous esophageal SCC, with an odds ratio (95% confidence interval) of 2.37 (1.06-5.31). CONCLUSION: Multiple foci of dilated vascular area is a useful predictor for stratifying the risk of metachronous esophageal SCC.

Endoscopic resection for local residual or recurrent cancer after definitive chemoradiotherapy or radiotherapy for esophageal squamous cell carcinoma.

Chemoradiotherapy (CRT) and radiotherapy (RT) are treatment options for esophageal squamous cell carcinoma (ESCC), but local residual/recurrent cancer after CRT/RT is a major problem. Endoscopic resection (ER) is an effective treatment option for local residual/recurrent cancer. To ensure the efficacy of ER, complete removal of endoscopically visible lesions with cancer-free vertical margins is desired. This study aimed to identify the endoscopic parameters associated with the complete endoscopic removal of local residual/recurrent cancer. In this single-center, retrospective study, we used a prospectively maintained database to identify esophageal lesions that were diagnosed as local residual/recurrent cancer after CRT/RT and treated by ER between January 2012 and December 2019. We evaluated the associations of endoscopic R0 resection with findings on conventional endoscopy and endoscopic ultrasonography (EUS). In total, 98 lesions (83 cases) were identified from our database. The rate of endoscopic R0 resection was higher for flat lesions (100% versus 77%, P = 0.00014). EUS was performed for 24 non-flat lesions, and endoscopic R0 resection was achieved for 94% of lesions with an uninterrupted fifth layer. Flat lesions on conventional endoscopy and lesions with an uninterrupted fifth layer on EUS are good candidates for ER.

Feasibility of underwater endoscopic mucosal resection for endoscopic management of gastric neoplasms in patients with familial adenomatous polyposis.

BACKGROUND: Underwater endoscopic mucosal resection (UEMR) has been developed as an effective endoscopic intervention for colon, rectum, and duodenum neoplasms. However, there are no comprehensive reports regarding the stomach, and its safety and efficacy are unknown. We aimed to examine the feasibility of UEMR for gastric neoplasms in patients with familial adenomatous polyposis (FAP). METHODS: We retrospectively extracted data of patients with FAP who underwent endoscopic resection (ER) for gastric neoplasms at Osaka International Cancer Institute from February 2009 to December 2018. Elevated gastric neoplasms of ≤ 20 mm in diameter were extracted, and conventional endoscopic mucosal resection (CEMR) and UEMR were compared. Furthermore, outcomes after ER until March 2020 were examined. RESULTS: 91 endoscopically resected gastric neoplasms were extracted from 31 patients with 26 pedigrees, and 12 neoplasms underwent CEMR and 25 neoplasms underwent UEMR was compared. The procedure time was shorter for UEMR than for CEMR. There was no significant difference between en bloc resection and R0 resection rates by EMR methods. CEMR and UEMR showed postoperative hemorrhage rates of 8% and 0%, respectively. Residual/local recurrent neoplasms were identified in four lesions (4%), but additional endoscopic intervention (three UEMR and one cauterization) resulted in a local cure. CONCLUSION: UEMR was feasible in gastric neoplasms of FAP patients, especially in elevated lesions and those of ≤ 20 mm in diameter.